An operator station of this type is currently obtained by superimposing or mechanically linking several parts, of which each can move in the direction of one axis only of the orthogonal trio of Cartesian coordinates and/or perform rotary movements, all such traversing and rotation movements being necessary to impart the various advance, working and adjustment movements of the various tools and/or workpieces.
This of necessity means that each superimposed part forming the station has to be constructed in such a way as to afford sufficient rigidity and enable the required working precision, thus entailing massive, heavy structures.
In addition, as the parts that have to traverse in relation to each other along the required direction are interconnected by a sliding guide system, these guides must be very carefully constructed to ensure that the machining tolerances and play between the parts forming the guides of the various parts that are suprimposed or interconnected with each other to form the operator station, do not compromise the required degree of machining precision, when all the effects of their imprecisions and vibrations are combined.
A final disadvantage that cannot be overcome with operator stations as per the present state of the art lies in the fact that, when carrying out a grinding operation, the minute fragments of abrasive of the (grinding wheels*) used inevitably tend to fall onto the parts of the machine below, penetrating the sliding guides between the parts or between these and the base support, with the obvious results of serious damage to these parts. These stations thus cannot normally be used to handle grinding operations as well, unless there are expensive complex mechanical devices to prevent the action of minute grinding fragments as described above.
In summarizing the above disadvantages, it can be seen that multiple operator stations according to the present state of the art are more expensive and cumbersome, with relative difficulty in achieving working precision, and with the limitation of not normally being able to handle grinding work amongst other tasks.